A champion of individual liberty and private property and foe of government intervention in business and personal affairs, Epstein has for decades been renowned as one of the nation’s leading intellectual exponents of libertarian conservatism. But in recent remarks about The Classical Liberal Constitution, his newly published book that he calls “a lifetime summation,” Epstein discussed a process of ideological “retooling” that he has undergone. “I emerged,” he said, “from somebody who was libertarian through and through to somebody who managed to think that there were systematic weaknesses associated with that position which required serious discourse and switching the title ‘libertarian’ to ‘classical liberal.’ ”

Rooted in the ideas of Locke, Hume, Madison and other Enlightenment thinkers, classical liberalism, Epstein explains in the book, guided the drafting of the Constitution and held sway in US Supreme Court jurisprudence through the first third of the 20th century. It was dismantled by the Court’s capitulation to the economic and social regulation of the New Deal, and since then, not just Democrats, but a broad swath of the political spectrum, has acceded to the “progressive” (or “social democratic”) view of individual rights and the role government. “My full-throated defense of classical liberal positions leads me to conclusions on many issues that are at sharp variance to those of both modern liberals and conservatives,” he writes.

Epstein’s differences with modern liberals will surprise no one. But those who have followed his work say his evolution away from more orthodox libertarianism has gone less noticed. “This is not the book that Richard would have written 25 years ago,” says Samuel Issacharoff, Bonnie and Richard Reiss Professor of Constitutional Law.

Professor Christopher Sprigman, who first got to know Epstein in the early 1990s, when he was a student and Epstein a professor at the University of Chicago Law School, agrees: “Richard’s understanding now of how history and path-dependency complicate principled constitutionalism is far more supple compared with the understanding he had a quarter century ago.”

No one expects Epstein to slap a Hillary 2016 bumper sticker on his car anytime soon, but areas in which Epstein’s views have moderated include the following:

Antitrust – As a “libertarian hard core” in the 1960s and 1970s, Epstein says, “I tended not to think that contracts in restraint of trade should be illegal because of the absence of force and fraud.” If Coke and Pepsi wanted to fix a minimum price for a can of soda, so be it – market forces would ultimately come to the rescue. “But as I mellowed, I came to the opposite conclusion,” Epstein says, and he now appreciates that “the cartelization of commerce is a serious threat that no one can ignore.”

Regulation of complex markets – Overall, Issacharoff notes, shifts in Epstein’s outlook have been prompted by “an expansion of the domain of state conduct that he thinks is necessary.” For example, while his default position is to favor the common law regulatory mechanisms of tort and contract, Epstein has become more concerned about the chaotic nature of such regulation in complicated markets, such as pharmaceuticals. He is thus more inclined, says Issacharoff, to favor "the superior coordination function of strict federal guidelines and the preemptive force they have over common law suits.”

Affirmative action – While Epstein used to be quite suspicious of affirmative action, “now he is far more institutionally pragmatic,” says Issacharoff. He and Sprigman credit the change in part to Epstein’s experience as law school administrator—he served as interim dean at the University of Chicago Law School in 2001. Indeed, as the Supreme Court has considered a series of cases involving racial-preference programs at universities during the past few years, Epstein has generally called on the justices to be hands off. “Universities and colleges struggle to make considered trade-offs between diversity and academic merit … to produce the best institution they can,” he wrote in a Defining Ideas column, and the Court should give deference to the good faith decisions individual school systems make about their programs.

Same-sex marriage—Epstein has noted that the crosscurrents of individual liberty, federalism, and original intent make gay marriage a “libertarian’s dilemma,” and, as gay marriage cases landed on the Supreme Court docket, he was torn on the proper course of action for the justices. In Defining Ideas, he acknowledged being swayed by the “huge sea change in popular sentiment” on the issue and wrote, “Gay marriage is a case where the legal norms would do well to get in line with social practices.”

Epstein’s path from libertarian to classical liberal is not merely an exercise in rebranding. It reflects a willingness to adjust his positions in response to arguments made by others, as well as to on-the-ground facts as law plays out in the real world—a mindset that is dynamic, not doctrinaire.

“I wouldn’t say that Richard has changed his mind about essential tenets of his thought, but he has rethought the way his principles actually work out in the formulation of law and policy,” says Sprigman. The fully-realized power of Richard’s thinking grows from his understanding of how principle doesn’t just yield to pragmatism, but can include it.”